Regardless of industry, sector or field, there’s one universal proclamation that is uttered by virtually all new project managers; especially if, alas, they’ve had the glorious mantle of project management thrust upon them: “I figured this would be a lot easier!”
Now, this shock and awe isn’t because project management is excessively complex compared to other professional roles. Rather, it’s because from the outside looking in, project management can seem deceptively simple. And one of the best — or perhaps worst — examples of this is when it comes to creating project dependencies.
What are Project Dependencies?
Understanding project dependencies isn’t the hard part: they’re the logical schedule links between two work items (e.g. tasks, milestones or activities), and which define their sequence. Sound simple? Yes, but only because we’re merely talking about what dependencies are. Applying them to a complex project schedule is where the proverbial rubber hits the road — and where things can get complicated and chaotic in a hurry.
The Problem with Project Dependencies
The core challenge with applying project dependencies is that there are four dependency relationships and four dependency types — and many (if not most) new project managers focus on the former and ignore the latter. That is, until their project runs off the rails and they’re forced to do some rapid course correction, or in extreme cases, pull the trigger on a schedule re-baseline.
The Four Dependency Relationships
As mentioned, there are four dependency relationships:
- Finish to Start (FtS): The successor work item begins upon completion of the predecessor work item.
- Finish to Finish (FtF): The predecessor work item does not finish until the successor work item is finished.
- Start to Finish (StF): The successor work item does not finish until the predecessor work item starts.
- Start to Start (StS): The successor work item does not start before the predecessor work item starts.
Again, most new project managers — or those who are temporarily working in a project management role (funny how that happens, huh?) — have a solid grasp of dependency relationships. That’s not to suggest that identifying them is easy and can be done in between games of Candy Crush. But dependency relationships are logical, and figuring out whether a specific relationship should be designated FtS, FtF, StF or StS usually doesn’t involve much research or analysis. Now for the tricky part.
The Four Dependency Types
In addition to being FtS, FtF, StF or StS, project dependencies also fall into one of four type categories:
- Mandatory: these are dependencies that are legally or contractually required, or are inherent in the work itself (sometimes called “hard logic”).
- Internal: these are dependencies that the project team defines and controls.
- External: these are dependencies that are dependent on activities outside of the project team’s control.
- Discretionary: these are dependencies that could be defined in more than one way (i.e. the relationship is not truly dependent), and that reflect the preferences of the project team.
But Wait — There’s More!
The other thing that project managers need to remember, is while there are four dependency types (as described above), only two can exist for a specific dependency relationship. Here are the only valid combinations:
- Mandatory Dependency + External Dependency
- Discretionary Dependency + External Dependency
- Mandatory Dependency + Internal Dependency
- Discretionary Dependency + Internal Dependency
The nice thing about this combination rule is that it makes logical sense — which means there are no confusing formulas to memorize (which should come as welcome relief to the certification exam-takers out there!). A mandatory dependency cannot also be a discretionary dependency. Similarly, an internal dependency cannot also be an external dependency. And so, once a project manager determines that a dependency relationship is:
- Internal, the question is: is it discretionary or mandatory?
- External, the question is: is it discretionary or mandatory?
- Mandatory, the question is: is it internal or external?
- Discretionary, the question is: is it internal or external?
The Bottom Line
Project management isn’t excessively difficult, but it’s certainly not as easy as it often looks from the outside and to the uninitiated (and anyone who believes otherwise will have a new and much humbler opinion very soon).
The safest, smartest and simplest way forward is to break complex concepts down into their basic elements, and in doing so, replace confusion with clarity, unawareness with competence, and doubt with confidence. It doesn’t happen overnight — in fact, it can take years — but the journey is rewarding, and the only required dependencies for project managers are an open mind and a love of learning.
